Metal-punching operation.



G. P. THOMAS.

METAL PUNCHING OPERATION.

APPLICATION FILED JUNE 7, 1915. 1,175,197. Patented Mar. 14, 1916.

4 SHEETS-SHEET I.

THE COLUMBIA PLANOGRAPH co.. WASHINGTON, D. c.

G. P. THOMAS.

METAL PUNCHING OPERATION.

APPLICATION FILEDIJUNE 1. 1915.

1, 1 75,197. Patented Mar. 14, 1916.

4 SHEETS-SHEET 2.

INVE TOR WITNESSES THE COLUMBIA PLANOGRAPH 60.. WASHINGTON, D. c.

G. P. THOMAS.

METAL PUNCHING OPERATION.

APPLICAHON FILED JUNE 7, I915.

Patented Mar. 14, 1916.

' 4 SHEETSSHEET 3.

G. P. THOMAS.

METAL PUNCHING OPERATION.

APPLICATION FlLED JUNE 1, 1915.

1,1 75,1 97. Patented Mar. 14, 1916.

4 SHEETS-SHEET 4.

INVENTOR THE COLUMBIA PLATIIOGRAPH c0. WASHINQTON. D. c.

GEORGE-PAUL THOMAS, OF GLENSHAW, PENNSYLVANIA.

METAL-PUNCHING OPERATION.

Specification of Letters Patent. Patented ll/Iar. 14, 1916.

Application filed June 7, 1915. Serial No. 32,594.

To all whom it may concern:

Be it known that I, GEORGE PAUL THOMAS, residing atGlenshaw, in the county of Allegheny and State of Pennsylvanla, a citlzen of the United States, have invented or discovered certain new and useful Improvements in Metal-Punching Operations, of which improvements the following is a specificaticn.

The invention described herein relates to methods of operating punching machines to the end that plates or like structural articles may be provided With holes lying in the arc of a circle or in arcs of concentric circles. 7

It is well known that, in plates intended to be used in the manufacture of boilers, tanks, stacks, conduits and like cylindrical or curved structures, it is necessary or desirable to have the finished form of the plate that of a portion of the curved surface of a cone. For example, in cylindrical stacks constructed of steel plates, it is desirable that the lower curved edge of each plate lie outside of the upper curved edge of the adjacent lower plate to which it is connected, the result being that each plate must be conical in form. Now to provide such plates with holes so that they may be accurately riveted together, the holes in the opposite curved edges of the plate must, before the plate is bent, lie in arcs of concentric circles; and furthermore, pairs of holes in opposite edges must lie in the lines passing through the center of such circles.

The problem that has continually confronted and vexed those concerned with the fabrication of such structures has been to provide a practical and feasible method of operating the essential punching machinery to the end that plates may be accurately punched in the manner described, and particularly when a considerable number of like plates are required. In thus speaking of essential punching machinery, I refer to such machinery as is now, and for a long time has been, considered indispensable in economic punching of structural material, namely a punch ng machine comprising a a punch and a work carriage movable to and from the punch and by which carriage the work is brought into proper positions for punching.

Various forms of punching machinery and method of operating the same have been suggested for the purposecontemplated --by of punching machinery, the punch is placed in position and the plate to be punched is,

while being supported on a carriage, swung bodily about the center of the are or arcs in which it is desired that the holes should lie. As examples of machines of this sort, reference may be had tothe disclosures of ;United States Patents No. 759,308 to Reeves and No. 793,051 to Chapman. Inthe former the tracks are curved in arcs of circles concentric with those in which it is desirable to punch the plate, and the carriage with its supported plate manifestly moves about the common center of curvature. the'plate is dragged by means of a carriage "moving in a straight line at right angles to the line of punches, and the plate, sl dable upon its supporting guides, is caused to move around the general center of curvature by means ofa curved guide. The principle of operation of machines of this general character is cCrrect-that is to say, the opposite edges of the plate may. be punched in true arcs'of concentric circles,

In the latter.

and the pairs of holes in such arcs will lie in lines passing through the center of curvaguides to suit the different required curvatures is both diflicult and time consuming, V and it is believed that it is for this reason ture of such arcs. However, it is apparent that the accurate bending of tracks for punching machinery, the punch is in fixed 1 straight line adjacent to it. The plate to be punched is carried upon a platform or table -position, and the carriage moves in a straight line guide, adapted to be adiusted' I at various angles to. the line of advance of the table, is provided to cause the table to turn on its pivotal axis as the-carriage advances. .type is shown in- United "States Patent'No.

Punching machinery of this 501,152 to Mohr. It has long been recognized that, while such punching machinery when operated in its intended manner will cause holes to be punched in curves, sucn.

curves are not the arcs of circles. The result is that when plates are punched with ,such machinery the holes will not match guide disposed at an angle to the carriage track or line of advance) so that plates may be punched with the same precise degree of accuracy as when punched by machinery of the first described type.

My invention proceeds upon my discovery, which having been made is capable of r precise demonstration, that by observing certain relations, which will be fully explained hereinafter, a plate may be punched with holes lying on concentric arcs of circles by pivotally mounting it on a carriage which is movable along straight line tracks adjacent to the punch, by causing the plate to rotate upon its pivotal axis while the carrings is advanced, and between successive punching operations causing the punch and carriage to move one with respect to the other in a direction transverse to that of the carriage advance.

In describing my invention reference is had to the accompanying sheets of drawings, wherein Figures 1 and 2 are diagrams of a plate and punches; Fig. 3 a plate showing convenient ways of determining distances for advance and lateral movements; Fig. 4 a combined sectional view of a work-carriage and end elevation of a punch on which my invention may be practised, the plane of view being indicated by the line IVIV, Fig. 5; Fig. 5 a sectional view and side elevation taken on the line VV, Fig. l; Fig. 6

a sectional view taken on the line VI VI,

Fig. 5; Fig. 7 a sectional view taken on the line VII-VII, Fig. 4; and Fig. 8 a planview of the work carriage and the portions of the punches adiacent thereto as illustrated invFigs. 4 and 5.

In the several figures likenumerals are used to designate like parts.

In describing my improved method in detail, I will first explain it with reference to the diagrammatic figures, and then with reference to the machinery.

In Fig. 1 I have indicated, in the most convenient relative positions for explanation, a plate tobe punched, the punches and the lines for determining the punching points and the travel of the plate. The plate A is pivoted substantially at its center 1, and this point is shown as lying in the line- (hereinafter referred to as the punching line) drawn between: the two punches 2 and 2,situated at opposite sides of the plate in positions to punch holes in the concentric arcs 3 and 3, respectively. The center of curvature of the arcs is indi cated at 4, and thepoints to be'punched are the intersections of the radial lines 5, 5, 5', 5 and 5 and the arcs 3 and 3*. Of course in actual practice many more holes are punched in each plate than for illustrative purposes are indicated in this figure. The

line of advance of the pivot point 1 is, as.

is indicated by the broken line 6, perpen dicular to the punching line, which is the usual practice in punching machinery for this purpose, although, as will presently appear, it is not essential to the practice of my invention that such, perpendicularity be observed. As will be seen, the plate A is indicated as being inthe proper position; to punch holes at the intersections of the radial line 5' with the arcs 3 and. 3 such radialline coinciding with the punching line.

I will now explain the essential movements of the punching machinery and plate to bring the parts to the proper relative positions to punch holes at the intersections of the line 5 with said arcs, it being understood .that the line 5 represents any line passing through the-center of curvature l and intersecting the arcs 3 and 3 In the first place it is necessary to determine the efiective point of engagement of the plate for turning it and at what angle to the line of advance 6 the straight line guide for such point must beset in order to properly turn the plate upon its pivotal point as the plate is advanced. When, as is usual, the line 6 1S perpendicular to the punching line, the effective point of engagement of the plate may be any point determined by the 1 intersection ofany radial line passing through the center of curvature 4 and a line perpendicular to such radial line and passing through the pivot 1, and. when such pivot lies in the punchingline, the guide line angle with the line 6 is the angle made between the line 6 and the line passing through the.

effective point of engagement; and the pivot:

point. For example, the point 7, being the point of intersection of the radial line 5 and a line 8 drawn perpendicular to the line 5 and passing through the be taken as the effective point of engagement of the plate. lVhen such point is thus chosen,-and caused to move along the line 8 as the pivot point 1 is simultaneously moved along the line 6, any radial line, as for example the line 5*, will be brought to the positionof the line 5', that is to say it will pivot point 1, may

be brought to a position wherein it coincides with the punching line. I

Fig. 2 shows the relative positions of the parts and lines when the plate is advanced and turned as thus described. It .will be observed first that the center of curvature 4 has moved from its former position i toward the punches 2 and 2 and along the punching line, and secondly that the point 7 has moved along the line 8 from its original position 7, the pivot point 1 remaining on the line of advance 6. That this relation actually exists may be readily demonstrated by a geometric consideration of the triangles 1, 45, 7" and 1, 4t, 7. It remains now to state that this advance movement and rotation of the plate A will not of itself bring the plate to a position to be punched on the arcs 3 and 8. There must be a relative lateral-movement between the plate and the punches, such movement being measured by the distance between the points 4 and P. This may be accomplished between successive punching operations either by moving the punches themselves or by simultaneously moving the work carriage, its straight line tracks represented by the line 6, and the guide represented by the line 8.

From the foregoing description certain relations will be readily understood without entering into further detailed explanations. In the first place it will be observed that as far as the movements of the parts are concerned, holes may be punched in any de sired number of concentric circular arcs, and that the plate to be punched may be any fraction or multiple of that shown. Such being the case. it will be seen that the effecti e point of the plate may be at any convenient point within or without the area of the plate. and that the effective point of engagement of the plate may be chosen as desired providing it fulfils the conditions alreadv explained. Furthermore, by a geometric consideration of the triangle 1 l 7 and 1, 4, 7, it will be seen that the line 6 is not necessarily perpendicular to the punching line;

Before explaining the construction and method of operation of a concrete example of punching machines in which my invention maybe practised, I will briefly describe a convenient way of determinlng the distances. which, between successive punching operations. it is necessary to advance the work carriage, and also the correspondlng increments of relative lateral movements between the carriage and punches.

Fig. 3 shows a plate A in which holes are to be punched on the concentric arcs 3 and 3 at their intersections with the several eauallv spaced vradial lines 5, 5", etc. The pivot point 1 of the plate is on the radial line 5 which is the middle of the several said lines, and the are 3 passes through the distances 0, cl and e represent the neceS- sarv advances to successively bring the radial lines 5, 5 and 5 to the punching-hue;

and, since the plate shown herein'is symmetrical about the radial line 5 the successive distances which the carriage must be moved to bring the radial lines 5, 5", 5 and 5 to the punching-line are, respectively, the distances 6, (Z, c and b.

Bearing in mind that the radial lines 5, 5, etc, are spaced evenly, the relative lateral movement between punchand carriage; which must be effected between the punching of holes on the radial lines 5 and 5 is the distance Z). As will be seen, this is the distance between a line drawn from the pivot point 1 perpendicular to the radial line 5 and a second line drawn from the intersection of the radial line 5 with'the,

arc 3 and parallel with the line'drawn from the point 1. This is true, of course, only when the space between the lines 5 and 5 is equal to that between 5 and 5 However. the principle underlying this manner of obtaining the lateral movement distances may be. applied when the spacing intervals are not equal by-layingoii onthe arc 3 the spacing intervals in the reverse order.

on the lines 5 5 and 5 are, respectively, a, (Z and 6. When the pivot point of the plate passes the radial line 5 the successive lateral movement d stances for punching on the lines 5, 5 5 and 5 are respectively 6, d, c and b, but in the opposite direction to the movements effected while the pivot point 1 approaches the punching line.

It will be understood that the two sets 7 of distances described above may be ob; tained in other ways. The procedures which I have indicated are simple and lend themselves readilv to computation or laying out in temnlet shop. Since the accuracy of their underlying principlesjmay be mathematically demonstrated, further explanations are unnecessary.

The punching machine illustrated herein is particularly adaptedto carryout the method of operation described above. The machine is not claimed in my present application. but except for the carriage driving mechanism, is fully claimed in another application, Serial No.

32,595,--fi-1ed of even date herewith. The

In a similar way the successive lateral movement distances for punching described and r carriage driving mechanism is described and l claimed in my earlier pending application, Serial No. 879,275. And because a full description of the several features of construction of the machinery shown herein is found in said applications, the present explanation connections, are thus moved. The work carriage comprises a truck frame 11 adapted to travel on suitable tracks 13, and a turn table 1 pivoted as at 1% to such table. The opposite ends of the table are provided with transversely extending longitudinally adjustable bars 15 and 15 which in turn carry clamps 16 for holding a plate in its adjusted position on the table; and, to cause the table to turn as the carriage advances, the bar 15 is further provided with a laterally adjustable block 17 to which an arm 18 is pivoted as at 19. This arm engages, at its outer end, a guide 20, which may be adjusted at any desired angle to the line of advance of the carriage; also the arm is, by means of a forked member 21 secured to the frame 11, held at substantially a constant angle to the line of advance of the carriage during such advance. In attaching to the carriage a plate, such as shown in Figs. 1, 2 and 3, the determined pivot point 1 of the plate is placed in vertical alinement with the pivot point 14 of the table, the plate is adjusted so that the radial line 5 will coincide with the punching line when the carriage has been advanced, and the block 17 is so adjusted laterally that the pivot point 19 of the arm 18 is in vertical alinement with the effective point of engagement 7 of the plate. Also, the guide 20 is adjusted so that it makes, with the line of advance of the carriage, the same angle as the line 7 makes with the line 6 (Figs. 1 and 2). Thus it will be seen that the effective point of engagement of the plate will be caused to follow the required line durin the advance of the carriage. I

Before describing the means for advancing and stopping the car "iage, I will briefly explain the construction and operation of the punching machines. They comprise frames and 22, mounted for lateral movements upon beams 23 and 23 and provided with punching heads 24: and 24 adapted to be reciprocated in the usual manner by the rotation of shafts 25 and 25 As will be seen the heads 2-1 and 24: are provided with punching tools 36 and 36 which correspond with the punches 2 and 2, diagrammaticallv shown in Figs. 1 and 2, and

In the present machine a with a stopping element. Figs. 4 and 5, the. stopping element 152 may driving connections from this shaft to the shaft 25 comprise pinions 30 31, shaft 32*, and pinions 38 and 3%; while the shaft 25 is driven through connections bearing similar reference characters, the pinions 30 being feathered to the shaft so that the punch frames may be adjusted with respect to each other. For effecting such adjust ment the punch frames are connected to each other by an oppositely threaded shaft 35, as

seen in Fig. 6. The lateral movement of the punches is, in this embodiment of myinven tion efi'ected manually. For this purpose the lower side of the frame is provided with a rack 37 which meshes with a pinion: 38. secured to a shaft 39 adaptedto be turned by a hand wheel. A0. The extent of each lateral movement of the punches may be determined visually, as by a pointer 41 secured to a support 42, and a scale 43 borne by the frame 22; or stopping mechanism may be provided for arresting the punches when they have been moved the required dis tances. As shown herein, such mechanism consists of bars stat and 44 provided with; adjustable stops and secured tothe support 42, and cooperating pawls 4:5 and 45 pivotally mounted on an arm 46 projecting laterally from. the frame through a rod l7, arm 48, shaft 49, arm 5O and cam 51 secured to the shaft 25 adapted, to be lifted from engagement from the stops of the bars 44 and he fter the completion of each punching stroke sothat the punches are free to be moved by turning the hand wheel L0 until .the next stop of a bar is engaged. The bars and their stops are arranged to arrest both the right and left lateral movements of the punches, which, as

already explained, is necessary when the. plate to be punched is pivoted at its center or other intermediate point. As to the spacing of the stops of the bars 4 and 44, it will be understood that they should be arranged at the intervals I), c,d', and c (Fig.

3), whether such intervals are obtained in the manner already explained or in some other way.

The means shown herein for effecting an intermittent advance of the carriage is inall essential respects the same as fully shown and described in my above mentioned appli-' cation, Serial No. 879,275. They comprise instrumentalities for causing the carriage,

between each punching stroke to move forwardly a distance greater'than' the largest spacing interval, and, after each of such ad-j vances, to move rearwardly into engagement As shown in -Thesepawls are,

be formed on the upper face of a bar 53,

supported beneath the center of the carriage, and adapted to be engaged by a pawl 54 secured to the truck frame 11. This frame is also provided with racks 55 adapted to mesh with pinions 56 secured to the shaft 57, which shaft extends to the left side of the punch frame 22. The rotation of the shaft 57 in opposite directions is accomplished in the same manner as shown in my above mentioned application, Serial No. 879,275, that is to say, by means of pawland-ratchet connections extending from the punch reciprocating shaft 25, as is shown in Fig. 7 of my present application. As to the arrangement of the detents or stopping elements 52, it will be understood that they are to be spaced at the intervals 6, 0, (Z, etc., (Fig. 3).

The operation of the machine shown herein is readily apparent from the foregoing description. After a plate to be punched has been properly adjusted on, and secured to, the table 12, the guide 20 adjusted to theproper angle with relation to the advance of the carriage, and detent bars 52 and A l, 44 properly adjusted, the machine may be set in operation by starting the motor 26. The punching heads will then be reciprocated, and the carriage intermittently advanced, by the coordinated driving connections already explained. The lateral movements of the punches will be effected by turning the hand wheel 40 in the required direction and between each punching stroke.

It will be understood that, while I have shown and described but one machine with which my invention may be practised, various other machines may be used, and a number of such other machines are shown and described in my application Serial No. 32,595 filed of even date herewith.

I claim as my invention:

1. In the operation of a metal-punching machine which includes in its structure a punch and a worl carriage, the method herein described which consists in causing the carriage to advance relatively to the punch, causing the work to rotate upon the carriage, and causing punch and carriage to move one with respect to the other in a direction transverse to that of the carriage advance first specified, said respective transverse movement including the point of rotation of the work upon the carriage, the said three movements being in progress as the work advances through the machine.

2. The herein described method of operating a punch and a work-carriage for punching through a plate a line of holes lying in the arc of a circle, which method consists of pivotally supporting a plate upon a carriage, advancing such carriage in a straight line adjacent to the punch, turning the plate on its pivot point during such advance of the carriage byguiding a point lying in the plane of the plate in a straight line intersecting the line of advance of'the carriage, and between the punching of successive holes effecting a relative movement between said punch and carriage in a direction transverse to the line of advance of the carriage, said lateral movement including the point of pivotal support, of the plate upon the carriage.

3. The herein described method of operating a metal punching machine comprising a multiple punch and work carriage whereby a plate may be provided with'holes lying in arcs of concentric circles, which method consists of pivotally supporting a plate upon a carriage, causing the carriage to advance in a straight line at right angles to the punching line of the multiple punch, causing the plate to rotate on its pivot point during such advance of the carriage and by guiding a point lying in the plane of the plate in a straight line intersecting the line of advance of the carriage, said point being that of the intersection of two lines at right angles to each other one passing through the pivot point of the plate and the other through the common center of curvature of the concentric arcs, and the angle between said straight line guide and the line of advance of the carriage being determinable with respect to the position of said point, and between the punching of successive holes effecting a relative movement between said punch and carriage in a direction at right angles to the line of advance of the carriage, said lateral movement including the point of pivotal support of the plate upon the carriage.

4. In the operation of a metal punching machine which includes in its structure a punch movable transversely with respect. to

GEORGE PAUL THOMAS.

Witnesses:

PAUL N. CRrroHLow, FRANoIs J. ToMAssoN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. I 

